The present invention relates to a method and apparatus for delivering particles of tobacco to a tobacco cutting machine, particularly to the system which transports a cake of tobacco particles into the range of one or more knives in a tobacco shredding machine.
Presently known tobacco shredding machines comprise convergent upper and lower chain conveyors which deliver a cake of condensed tobacco particles into the range of orbiting knives on a rotary carrier whereby the knives cut across the leader of the cake and convert the particles into smaller fragments or shreds which are delivered to a conditioning unit prior to transport into the magazine of a cigarette maker. The rear end of the lower chain conveyor extends beyond the rear end of the upper chain conveyor and receives a shower of tobacco particles from a duct. A rake or an analogous device is provided to push the descending particles into the space between the two chain conveyors whereby the conveyors convert the stream into the aforementioned cake whose density increases on the way toward the cutting station. The just described cutting machines are used for comminution of tobacco leaf laminae and/or tobacco ribs.
A drawback of presently known systems which deliver tobacco particles to the chain conveyors of a shredding machine is that the particles which form the cake are oriented in random fashion. This affects the homogeneousness of the cake and often results in extraction (rather than severing) of relatively large particles from the front end of the cake. Large fragments of ribs are likely to affect the quality of the filler of a cigarette rod and/or to puncture the wrapping material (cigarette paper) which is used to convert the filler into a rod ready to be subdivided into discrete cigarettes or analogous smokers' products.